Study on Control Quality of Valve Outlet Blockage Fault

2014 ◽  
Vol 983 ◽  
pp. 424-427
Author(s):  
Yan Tao An ◽  
Ru Jian Ma ◽  
Dong Zhao
Keyword(s):  
Flow Characteristic ◽  
Characteristic Curve ◽  
Control Valve ◽  
Differential Pressure ◽  
Pressure Flow ◽  
Relative Gain ◽  
Control Quality ◽  
Maximum Value

The flow characteristic and differential pressure-flow of outlet blockage fault and trouble-free for control valve are simulated by CFD. The study shows that the vortex at the bottom of control valve outlet is main reason for the outlet blockage fault, relative gain of flow characteristic curve for outlet blockage is increased, the flow percentage of outlet blockage compared with trouble-free is maximum value at relative opening is 60% and 100%, the pressure - flow percentage reaches maximum value at differential pressure is 800 kPa.

Study on Flow Characteristics of Valve Inlet Blockage

2014 ◽  
Vol 607 ◽  
pp. 294-297
Author(s):  
Yan Tao An ◽  
Ru Jian Ma ◽  
Dong Zhao
Keyword(s):  
Flow Characteristic ◽  
Characteristic Curve ◽  
Flow Characteristics ◽  
Control Valve ◽  
Differential Pressure ◽  
Pressure Flow ◽  
Relative Gain ◽  
Flow Change

The flow characteristic and differential pressure-flow of inlet blockage fault and trouble-free for control valve are numerical simulated by CFD. The study shows that relative gain of flow characteristic curve for inlet blockage is increased, and it enhances the influence on fluctuation to flow change. The flow is less than the trouble-free at the same pressure, and with the increase of the differential pressure, flow difference of comparing with trouble-free increases gradually.

Optimization of Nonlinear Pressure-flow Characteristics of a Spring- Loaded Pressure Relief Valve Based on CFD Simulation

2021 ◽  
Author(s):  
Chengshuo Wu ◽  
Shiyang Li ◽  
Qianqian Li ◽  
Peng Wu ◽  
Bin Huang ◽  
...  
Keyword(s):  
Flow Characteristic ◽  
Characteristic Curve ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Relief Valve ◽  
Pressure Flow ◽  
Hydraulic Force ◽  
Middle Chamber ◽  
Valve Opening ◽  
Cfd Method

Abstract In this study, the nonlinear pressure-flow characteristics of a spring-loaded pressure relief valve (PRV) which is used in the automotive fuel supply system for pressure control is analyzed, and its characteristics are improved by means of geometrical modifications of the valve structure. Given the complexity of the coupling mechanism between the valve internal flow characteristics and spring system, a quasi-steady computational fluid dynamics (CFD) method is introduced to predict the nonlinear pressure-flow characteristic curve of the valve and the accuracy is validated by experimental data. The total hydraulic force on the valve spool and diaphragm are divided into three parts according to the position of action and the correlation between the internal flow characteristics, hydraulic force, and pressure-flow characteristics of the valve are explained by CFD analysis and visualization. The result shows that the quasi-steady CFD method can accurately predict the trends of the valve nonlinear pressure-flow characteristic curve which is mainly determined by the hydraulic force produced in the middle chamber of the valve, when the valve opening reaches a certain value, a main vortex would be formulated in the middle chamber and lead to the sudden increase of hydraulic force which causes the fluctuation of the pressure-flow characteristic curve of the valve. It was also found that by increasing the round corner size, the valve opening value of flow pattern change will be promoted and the valve pressure-flow characteristic can be optimized.

scholarly journals Discovery and Evaluation of Protein Biomarkers as a Signature of Wellness in Late-Stage Cancer Patients in Early Phase Clinical Trials

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2443
Author(s):  
Bethany Geary ◽  
Erin Peat ◽  
Sarah Dransfield ◽  
Natalie Cook ◽  
Fiona Thistlethwaite ◽  
...  
Keyword(s):  
Overall Survival ◽  
Clinical Trials ◽  
Early Phase ◽  
Characteristic Curve ◽  
Performance Status ◽  
Area Under The Curve ◽  
Protein Biomarkers ◽  
Late Stage Cancer ◽  
Early Phase Clinical Trials

TARGET (tumour characterisation to guide experimental targeted therapy) is a cancer precision medicine programme focused on molecular characterisation of patients entering early phase clinical trials. Performance status (PS) measures a patient’s ability to perform a variety of activities. However, the quality of present algorithms to assess PS is limited and based on qualitative clinician assessment. Plasma samples from patients enrolled into TARGET were analysed using the mass spectrometry (MS) technique: sequential window acquisition of all theoretical fragment ion spectra (SWATH)-MS. SWATH-MS was used on a discovery cohort of 55 patients to differentiate patients into either a good or poor prognosis by creation of a Wellness Score (WS) that showed stronger prediction of overall survival (p = 0.000551) compared to PS (p = 0.001). WS was then tested against a validation cohort of 77 patients showing significant (p = 0.000451) prediction of overall survival. WS in both sets had receiver operating characteristic curve area under the curve (AUC) values of 0.76 (p = 0.002) and 0.67 (p = 0.011): AUC of PS was 0.70 (p = 0.117) and 0.55 (p = 0.548). These signatures can now be evaluated further in larger patient populations to assess their utility in a clinical setting.

A study on characteristics evaluation to control quality of asphalt mixture using X-ray CT

2014 ◽  
Vol 15 (4) ◽  
pp. 892-910 ◽  
Author(s):  
Satoshi Taniguchi ◽  
Jun Otani ◽  
Masayuki Kumagai
Keyword(s):  
Asphalt Mixture ◽  
X Ray ◽  
Control Quality

scholarly journals Performance of deep learning technology for evaluation of positioning quality in periapical radiography of the maxillary canine

2021 ◽  
Author(s):  
Mizuho Mori ◽  
Yoshiko Ariji ◽  
Motoki Fukuda ◽  
Tomoya Kitano ◽  
Takuma Funakoshi ◽  
...  
Keyword(s):  
Deep Learning ◽  
Characteristic Curve ◽  
Classification Performance ◽  
Learning Systems ◽  
Learning Technology ◽  
System 2 ◽  
Potential Benefits ◽  
System 1 ◽  
Periapical Radiography

Abstract Objectives The aim of the present study was to create and test an automatic system for assessing the technical quality of positioning in periapical radiography of the maxillary canines using deep learning classification and segmentation techniques. Methods We created and tested two deep learning systems using 500 periapical radiographs (250 each of good- and bad-quality images). We assigned 350, 70, and 80 images as the training, validation, and test datasets, respectively. The learning model of system 1 was created with only the classification process, whereas system 2 consisted of both the segmentation and classification models. In each model, 500 epochs of training were performed using AlexNet and U-net for classification and segmentation, respectively. The segmentation results were evaluated by the intersection over union method, with values of 0.6 or more considered as success. The classification results were compared between the two systems. Results The segmentation performance of system 2 was recall, precision, and F measure of 0.937, 0.961, and 0.949, respectively. System 2 showed better classification performance values than those obtained by system 1. The area under the receiver operating characteristic curve values differed significantly between system 1 (0.649) and system 2 (0.927). Conclusions The deep learning systems we created appeared to have potential benefits in evaluation of the technical positioning quality of periapical radiographs through the use of segmentation and classification functions.

scholarly journals An experimental study on the effects of swirling oxidizer flow and diameter of fuel nozzle on behaviour and light emittance of propane-oxygen non-premixed flame

2017 ◽  
Vol 21 (3) ◽  
pp. 1453-1462 ◽  
Author(s):  
Alireza Javareshkian ◽  
Sadegh Tabejamaat ◽  
Soroush Sarrafan-Sadeghi ◽  
Mohammadreza Baigmohammadi
Keyword(s):  
Reynolds Numbers ◽  
Flame Length ◽  
Nozzle Diameter ◽  
Fuel Flow ◽  
Maximum Value ◽  
Fuel Nozzle ◽  
Flame Shape ◽  
The Stability ◽  
Blue Flame

In this study, the stability and the light emittance of non-premixed propane-oxygen flames have been experimentally evaluated with respect to swirling oxidizer flow and variations in fuel nozzle diameter. Hence, three types of the vanes with the swirl angles of 30?, 45?, and 60? have been chosen for producing the desired swirling flows. The main aims of this study are to determine the flame behaviour, light emittance, and also considering the effect of variation in fuel nozzle diameter on combustion phenomena such as flame length, flame shape, and soot free length parameter. The investigation into the flame phenomenology was comprised of variations of the oxidizer and fuel flow velocities (respective Reynolds numbers) and the fuel nozzle diameter. The results showed that the swirl effect could change the flame luminosity and this way could reduce or increase the maximum value of the flame light emittance in the combustion zone. Therefore, investigation into the flame light emittance can give a good clue for studying the mixing quality of reactants, the flame phenomenology (blue flame or sooty flame, localized extinction), and the combustion intensity in non-premixed flames.

Sign in / Sign up

Export Citation Format

Share Document